Variable speed transmission device



Dec. 17, 1935. D. E. LEWELLEN ET AL 2,024,460

VAEIABLE SPEED TRANSMISSIQN DEVICE Filed Sept. 22, 1952 DarcyELeweZlen EPW011412? L ewe! 12/1 grime/HM.

Patented Dec. 17, 1935 VARIABLE SPEED TRANSMISSION DEVICE Darcy E. Lewellen and Emmons F. Lewellen, Columbus, Ind.

Application September 22, 1932, Serial No. 634,400

7 Claims.

This invention relates to improvements in variable speed transmission devices and the object of the invention is to greatly simplify mechanism of this character.

Referring to the accompanying drawing, which is made a part hereof and on which similar reference characters indicate similar parts,

Figure 1 is a plan view of the device,

Figure 2, a section on line 2-2 of Figure 1,. Figure 3, an enlarged sectional view of the belt. I

In the drawing numeral Ill indicates a frame having shafts II and I2 mounted in suitable bearings I3 and. I4 carried by the frame. The shafts extend beyond the sides of the frame and carry suitable sprockets, pulleys or gears, not shown, by means of which the shafts are driven or by means of which they drive other mechanism. Power is applied to the sprockets, pulleys or gears of \one of the shafts and power is taken off from the'other shaft in a manner well-known. Shaft II carries conical faced disks I 5 and shaft I2 carries similar disks "IS. The disks I5 are splined to the shaft II so as to slide axially upon the shaft but are keyed to rotate with the shaft. Collars H are secured to shaft II by set screws I8. Between these collars and the outside faces of the disks I5 are positioned springs I9, the springs surrounding extensions or hub portions 20 on the disks I5. The tension of the springs I3 may be varied by adjusting the collars l1 and securing them in adjusted position by the set screws Hi. The disks I 6 are splined to the shaft I2 so as to rotate with the shaft but are permitted to move axially on the shaft. The disks I6 have projecting hubs 2i on which hubs are mounted thrust bearings 22. These thrust bearings have projecting bosses 23 which extend through levers 24 by means of which levers the disks I6 are moved toward and from each other.

A V-shaped belt 25 is positioned about the disks by means of which one shaft is driven by the other. The belt may be any suitable belt, the edges of which are shaped at an angle to correspond to the angle on the inner faces of the disksi5 and I6. One convenient form of belt is shown in section in Figure 3. In this figure blocks 26 and 21 are secured to a band 28 by means of bolts, rivets or any other suitable way. To the ends of the blocks 26 and 21 are attached friction tips or" butts 29 which tips engage the inner conical faces of the disks l5 and I6. The disks I5 are held in engagement with the sides of the belt by means of the springs I9. Tension on these springs may be adjusted by moving the collars l1 axially along the shaft II.

The frame ID has inwardly extending lugs 30 to which links 3| are attached and the ends of 5 the levers 24 are pivotally attached at 32 to the links 3i. A shifting screw 33 is journaled in the frame Ill and carries an operating wheel 34 on its outer end. This screw is threaded with right and left hand threads 35 and 36 which 10 threads extend through shifting nuts 31 and 38 respectively. These nuts have bosses 39 and 40 which extend through slots 4| in the ends of the levers 24.

From the description given it will be apparent 15 that rotation of the hand wheel 34 in one direction will move the left end of thelevers 24 toward each other and in the other direction will move these levers away from each other, thus moving the disks l6 toward or from each other. When- 20 the disks I6 are moved toward each other the inner conical face forces the belt 25 radially outwardly on the disks. While the disks I5 will be moved outwardly against the tension of springs I9 to decrease the circumference about 25 which the belt 25 travels on the conical surfaces on the inside of the disks I5. 4

Either one of the shafts II and I2 may be the driving and the other the driven shaft.

For purposes of description assume that the 30 shaft II is driven from some source of power, the shaft I2 is driven from shaft II and that the shaft l2 drives the mechanism which operates the work.- When the shaft 33 is rotated clockwise as viewed upwardly in Figure 1 the disks 35 I6 will be moved from each other. This permits the belt 25 to move in closer to the shaft I2. The springs I 9 pressing on the disks I5 move these toward each other and the belt is caused to travel about a larger surface on the conical 4 surface of the disks l5. Since II is the driving shaft this will increase the speed of the shaft I2. When the shaft I3 is rotated in a counterclockwise direction, the disks I6 will be brought toward each other so that the shaft I2 will be 45 .driven at a slower rate of speed. It will be tion. It will be noted further that there are no thrust bearings on the disks l5, They are resiliently held at all times in friction driving contact with the belt 25. Only one set of disks is positively operated by the levers 24. By virtue.

of the bosses 23 engaging the levers and the construction and mounting of the levers 24 there is a uniform load on the thrust bearings 22 at all times.

It will be obvious to those skilled in the art that various changes may be made in our device without departing from the spirit of the invention and therefore we do not limit ourselves to what is shown in the drawing and described in the specification, but only as indicated by the appended claims.

Having thus fully described our said invention, what we claim as new and desire to secure by Letters Patent, is:

1. A variable speed transmission comprising a frame, a pair of parallel shafts journaled in the frame, a pair of disks on each shaft, said disks having adjacent cone faces, a belt about said disks having its edges in contact with the faces of the cones to transmit power from one shaft to the other, a pair'of levers pivoted to the disks on one shaft for moving the said disks, and resilient means on the other shaft and biased to urge said disks toward each other to hold the cone faces in frictional and driving engagement with the edges of the belt, substantially as set forth.

2. A variable speed transmission device comprising a frame, a pair of parallel shafts mounted in the frame, a pair of disks on each shaft, said disks having adjacent cone faces, a belt mounted about said disks with its edges in contact with the cone faces on the disk for transmitting power from one shaft to the other, a pair of levers pivotally attached to the disks on one shaft, manually operable means for moving said levers simultaneously in opposite directions, and resilient means for urging the disks on the other shaft toward each other to keep them at all times in frictional driving contact with the edges of the said belt, substantially as set forth.

3. A variable speed transmission device comprising a frame having a pair of parallel shafts mounted thereon, a pair of disks on each shaft, said disks having adjacent cone faces, a belt mounted about said disks for transmitting power from one shaft to the other, a pair of springs about one shaft, said springs having their inner ends in engagement with the outer faces of the disks to urge the disks into frictional driving engagement with the said belt, a pair of levers pivotally connected to the disks on a second shaft, said levers being also connected to the said frame and an operating shaft journaled in said frame and operably connected to the said levers for moving the levers simultaneously in opposite directions, substantially as set forth.

4. A variable speed transmission device comprising a frame, a pair of parallel shafts jour-' naled in the said frame, a pair of disks on each. shaft, said disks having adjacent cone faces, r;

belt positioned about the said disks having its edges in frictional driving engagement with the disks for driving one shaft from the other, means for changing the relative speeds of .the two shafts comprising a pair of springs on one shaft, said 5 springs having their inner ends in engagement with the disks on this shaft for urging them toward'each other, a pair of levers pivot-ally connected to said frame and operably connected to the disks on the other shaft for moving these 10 disks toward and from each other, and an operating shaft journaled in the said frame and having screw threads thereon engageable with nuts on the said levers for moving the levers toward or from each other upon rotation of the 15 said operating shaft, substantially as set forth.

5. A variable speed transmission device comprising a frame, a pair of parallel shafts mounted on the frame, a pair of disks on each shaft, said disks having adjacent cone faces, a 20 belt trained about said disks having its edges in engagement with the cone faces on the disks for driving one shaft from the other, resilient means on one shaft positioned to urge said disks toward each other, a pair of links pivotally at- 25 tached to the sides of the said frame, levers attached to the said links, said levers being pivotally attached to the disks on the other shaft, an operating shaft journaled in the said frame and connected to the said levers for moving them 30 toward or from each other upon rotation of the operating shaft, the said resilient means moving the disks on the other shaft to maintain the belt at all times in driving contact with the said disks, substantially as set forth.

6. A variable speed transmission comprising a pair of parallel shafts journaled on fixed axes, a pair of disks on each shaft, said disks having adjacent cone faces, a belt about said disks having its edges in engagement with the faces of 40 the cones for transmitting power from one shaft to the other, manually operable means engageable with the disks of one shaft for moving them simultaneously and equidistantly toward or away from each other, and resilient means on 5 the 'Other shaft and biased to urge said disks toward each other to hold the cone faces of the disks in driving engagement with the edges of the belt.

7. A variable speed transmission device 'com- 50 prising a frame, a pair of parallel shafts mounted on the frame, a pair of disks on each shaft,. said disks having adjacent cone faces, a belt mounted about said disks with its edges in contact with the cone faces on the disks for transmitting power from one shaft to the other, an operating shaft journaled in the said frame, means engageable with the said disks and operated by said last-named shaft for moving the disks on one of the parallel shafts simultaneously and equidistantly toward and from each other, and resilient means on the other of said parallel shafts biased to urge said disks toward each other to hold the cone faces in driving contact with the edges of the belt.

DARCY E. LEWELLEN. EMMONS F. LEWELLEN. 

